Field of the Invention
The present invention is related to a coolant control valve that selectively supplies an EGR cooler with coolant, which selectively circulates an EGR cooler with coolant depending on a driving condition of an engine instead of an EGR valve.
Description of Related Art
Generally, in a vehicle, fuel is burned in a cylinder to be expended, and then exhaust gas is exhausted to an outside through an exhaust manifold.
Most of the exhaust gas is vapor and CO2, and includes carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx).
An exhaust gas recirculation system reduces nitrogen oxide of the exhaust gas by recirculating exhaust gas to an intake manifold such that combustion temperature is lowered and the nitrogen oxide is reduced, when air fuel mixture is combusted.
Then, the combustion speed is reduced, if the increment of the combustion temperature is suppressed, resultantly, the nitrogen oxide can be reduced.
Meanwhile, an exhaust gas recirculation valve is disposed between an exhaust manifold and an intake manifold and opens or closes a circulation line by controlling an EGR valve in a specific rotation area.
An EGR valve is opened depending on an opening rate of a throttle valve to recirculate exhaust gas to an intake manifold of an engine such that the output decrement of the engine is minimized and combustion temperature is decreased to amount of the nitrogen oxide (Nox).
The exhaust gas recirculation device includes an EGR pipe, an EGR valve that is disposed on the EGR pipe to open or close the EGR pipe, and an EGR cooler that is disposed on the EGR pipe to cool the recirculation gas passing the EGR pipe.
An inlet is formed at one side of the EGR cooler to receive the coolant of an engine, and an outlet is formed at the other side thereof to exhaust the coolant that cools the recirculation.
Meanwhile, an EGR coolant valve is disposed to control the coolant passing the EGR cooler, the cost is increased due to the EGR coolant valve, and a separate actuator is necessary to control the EGR coolant valve.
FIG. 7 is a schematic diagram showing an EGR cooler that is related to the present invention. Referring to FIG. 7, the figure includes an EGR line 710, an EGR cooler 560, a bypass line 700, a bypass valve 730, and an EGR valve 720.
EGR gas that is recirculated from an exhaust line to an intake line passes an EGR line 710 and an EGR cooler 560 to join the intake line, the EGR gas flow the bypass line 700 bypassing the EGR cooler 560, and a bypass valve 730 is necessary and a separate actuator is also necessary.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.